Dear friend,
It is fine to use cat frontline on dogs as long as you do not use dog flea meds on cats.
I am so sorry your babies are troubled with fleas. You dont need any harsh products.
All you have to do is put down some Diatomaceous earth in your yard and a few pots in the house and you and your baby will never see another flea, fly, worm, etc.
Get it at a garden shop or online:
http://wolfcreekranch1.tripod.com/defaq.html
http://www.internet-grocer.net/diatome.htm
I am in Florida where fleas/bugs/worms are active 24/7/365 and it works like a charm for me.
I hope your babies get relief very fast.
Best wishes,
Terri
Healthcare Expert
Expert in canine health and behavior. 20 years of experience with dogs